Condenser and method of making the same.



ALBERT rnunssuau, or aaawrn, rumors,

PANY, mcoaroaa'rnn, or raw Yoax, n. r,

ABSIGNOB T WESTERN ELECTRIC OOH- A GOBPOBATION OF NEW YORK.

CONDENSER AND METHOD OF MAKING THE SAME;

1,275,468. No Drawing.

To all whom it may concern:

Be it known that I, ALBERT Panassams,

a citizen of the United States, residing at Berwyn, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Condensers and Methods of Making the Same, of which the following is a full, clear, concise, and exact description.

This invention relates to condensers and a method of making the same, its ob%ect being to provide an improved method 0 treating condensers to revent a permanent change in their electrical constants as a result of 16 normal temperature changes.

In composite circuits, which are used for thesimultaneous sending of telephone and telegraph messages, the requirements are such as to demand condensers which are 20 very closely balanced in electrical constants with respect to each other. Also in connection with various other electrical circuits or networks, there is a considerable demand for condensers,

are necessarily held to very close limits in order that the circuits may function properly. By following a process of selection, it is ossible to obtain groupsof condensers whic initially meet the various require- 80 ments, but experience has shown that such condensers, even thou h made in the same manner and in fact' 1n the same lot, may

vary considerably from each other after being subjected to temperature changes to 85 be expected under normal operating conditions. It is; rtherefore, the object of, the

present invention to provide a method of treatment which, when ap lied to the stand- 1 ardttype of condensers, wi l insure that their '40 electrical constants are not permanently affected to an appreciable amount by normal changes in temperature.

The type of condensers most commonly used in telep one practice consists of alternate strips or layers of metal foil and insulating material, such as paper, rolled into a cylindrical or elliptical form. After this unit is wound, it is given a treatment to make it impervious to moisture. Various methods are employed to attain this resulti one which has beeiifound to be afticular y satisfactory being described n detail in United anted to. the ap- States Patent 1,127,513,

1 15. .This method plicant on February 9,

Specification of Letters Patent. Application 11.4 m 21, 1911. Serial No. 188,181.

the unit is the electrical constants of which- Patented Aug. 13, 1918.

consists essentially in bakin the wound unit to expel all moisture, and t en boiling it in melted paraflin wax or an equivalent material. As the unit is allowed to cool, it is shaped by slight pressure applied to the flat sides thereof, after which it is dip into an insulating compound and t placed in a metal container which is later completely filled with the insulating compound.

The additional treatment contemplated by this invention consists in placing the treated unit in an oven, which is maintained at a temperature greater than the melting oint of the impregnating wax and leaving it at this temperature for a 'ven period of time, after which it is allowe to cool. During this treatment, any stresses,-.due to unequal winding or unequal pressures during the shapin process become equalized and free to talre its natural shape, or,

so to speak, to take a ermanent set, after which there will be no urther tendency for change in. shape, even though the impregnating wax is in a fluid state. In the case of condensers which are impregnated with a paraflin wax, the solidifying temperature of which is approximately 120 F., a satisfactory treatment has been found to consist in placing the condensers in an upri ht position in an oven, the tem rature 0 which is maintained at approximately 14 jF., and leaving them there for a erlod of from four to six hours, after whic they are allowed to cool- Extensive tests made on condensers so treated indicate that no appreciable change of a permanent nature w ll takeplace as a result of temperature changes such as would be experienced under normal operating conditions.

What 18 claimed is:

1. The method of treating a condenser comprising an impregnated unit, which 0011- sists in heating said impre ated un1t to a temperature greater than t e meltm point e impregnating compound; an mamtem erature for a taining the unit at such ow the unit to period of time sufficient to al assume its natural shape.

2. The method of treatin comprising a umt impregna fin compound, which consists in heati the impregnated unit to a temperature of 11 less than 120 F., and maintaining said unit at a condenser with a parafthis temperature for a period of not less of 140 F., and mainteinin it at this temthan three hours. rature for a period of en ntially four 3. The method of treating a condenser ours. comprising. a unit im ;l egnabed with a In witness whereof I hereunto subscribe 5 paraflin compound, whic consists in 1110- my name this 25th day of July, A. D. 1917.

mg the impregnated unit in an uprigh positlon in an oven heated to a temperature ALBERT PRUESSMAN.

mer in Letters Patent No 1,275,468-

Disciai .ing point of the impregnating compound,

1,275,468.-Albrt Prueasman,

MAKING THE Same. Patent 15, 1920, by the patentee, the assignee, W consenting. Enters this disclaimer to wit:

1. The method of treating a condenser eemprising an impregnated unit, which consists in heating said impregnated unit to a temperature greater that the meltand maintaining the unit at such temperature for a period of time euffieient to allow the unit to assume its natural shape.

2. The method of treating a condenser comprising a unit impregnated with a paraffin compound, which consists in heating the impregnated unit to a temperature bf not less than 120 F., and maintaining said unit at thietemperature for a period of not less than three hours.

3. The method of treating a condenser pomprising a' unit impregnated with a paraffin compound, whieh consiste in placing the impregnated unit in an upright position in an oven heated to a temperature of 140 F.,1and maintaining it at thin temperature for a period of substantially four hours."

[Qflicidl Gazette July 18,-1980J To claims 1, 2, and 3 of said Letters Patent, which are in the following words; 

